Electronic apparatus

ABSTRACT

An electronic apparatus disclosed facilitates the replacement of an input device. In the electronic apparatus equipped with the input device allowing various input operations, the input device including first signal generators is positioned by being placed in an opening of a housing from the outside. A cover can be detached from the housing and fixes the input device when installed in the opening of the housing. Second signal generators are provided inside the housing and function in combination with the respective first signal generators. Just mounting the cover to the housing fixes the input device. This facilitates the replacement of the input device, eliminating the need to open the housing and to remove a wiring board mounted with the second signal generators in replacement of the input device.

TECHNICAL FIELD

The present invention relates to an electronic apparatus equipped withan input device enabling various inputs when an operating memberundergoes required operation.

BACKGROUND ART

Recently, electronic apparatuses equipped with various input deviceshave come into widespread use. One of such conventional electronicapparatuses will be described hereinafter with reference to FIG. 14.

FIG. 14 is a perspective view of an essential part of the conventionalelectronic apparatus.

As shown in this drawing, terminal 2 of input device 1 is electricallyand mechanically connected in place to wiring board 3 of the electronicapparatus by soldering, whereby input device 1 is mounted to wiringboard 3.

This input device 1 includes operating member 4 projecting upward. Whenan operator moves operating member 4 in a specified direction with ahand or a finger, input device 1 outputs an electric signalcorresponding to this operation.

This electric signal is sent from terminal 2 of input device 1 to amicrocomputer (not shown) or the like of the electronic apparatus viawiring board 3, and consequently, the electronic apparatus starts aspecific function corresponding to this signal.

A top side of housing 5 serving as an upper case of the electronicapparatus has opening 5A permitting the passage of operating member 4 ofinput device 1. Through this opening 6A, only operating member 4projects on the top side of housing 5.

A variety of functions of the thus-configured conventional electronicapparatus equipped with input device 1 can be started by manipulatingoperating member 4 of input device 1 that projects upward from housing 5or is exposed over housing 5.

Failed input device 1 of the conventional electronic apparatus describedabove is replaced in the following manner.

Housing 5 of the electronic apparatus is opened, and wiring board 3 isremoved. Subsequently, failed input device 1 is removed by detachingsoldered terminal 2 of input device 1 from wiring board 3. Thereafter, anew input device is mounted to wiring board 3, and the electronicapparatus is reassembled. The replacement is thus extremely troublesome.

DISCLOSURE OF THE INVENTION

An electronic apparatus of the present invention includes an inputdevice, a housing, a cover, and a second signal generator.

The input device includes a first signal generator. The housing includesan opening in which the input device is placed externally andpositioned. The cover can be detached from the housing and fixes theinput device when installed in the opening of the housing. The secondsignal generator is provided inside the housing and functions incombination with the first signal generator.

The input device installed in this electronic apparatus can be removedby just detaching the cover from the housing. Thereafter, placing a newinput device in the opening and reinstalling the cover on the housingare all that is needed to allow the new input device to functionelectrically and mechanically. The replacement of the input device isthus easy, eliminating the need to open the housing and to electricallyreconnect the second signal generator provided inside the housing.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an exploded perspective view of an electronic apparatus inaccordance with a first exemplary embodiment of the present invention.

FIG. 2 is a conceptual illustration of a housing seen from inside thehousing when a cover, which is an essential element in the firstembodiment, is mounted.

FIG. 3 is an exploded perspective view of an electronic apparatus inaccordance with a second exemplary embodiment of the present invention.

FIG. 4 is a sectional view of the electronic apparatus of FIG. 3.

FIG. 5 is a top plan view of the electronic apparatus of FIG. 3 fromwhich a housing and a case of a trackball device are omitted.

FIG. 6 is a sectional view taken along line A-A of FIG. 5.

FIG. 7 is a top plan view of the electronic apparatus of FIG. 3 fromwhich the housing, the case of the trackball device, a ball and rollersare omitted.

FIG. 8 is a sectional view taken along line X-X of FIG. 5, illustratingthe trackball device in rolling operation.

FIG. 9 is a sectional view taken along line X-X of FIG. 5, illustratingthe trackball device in pressing operation.

FIG. 10 is a top plan view of an electronic apparatus, from which ahousing, a case of a trackball device, a ball and rollers are omitted,in accordance with a third exemplary embodiment of the presentinvention.

FIG. 11 is a perspective view of an essential part of an electronicapparatus in accordance with a fourth exemplary embodiment of thepresent invention.

FIG. 12 is an exploded perspective view of the electronic apparatus ofFIG. 11.

FIG. 13 is a sectional view taken along line B-B of FIG. 12,illustrating the electronic apparatus in complete condition.

FIG. 14 is a perspective view of an essential part of a conventionalelectronic apparatus.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Exemplary embodiments of the present invention will be demonstratedhereinafter with reference to the accompanying drawings.

Exemplary Embodiment 1

FIG. 1 is an exploded perspective view of an electronic apparatus inaccordance with the first exemplary embodiment of the present invention.

FIG. 2 illustrates a housing seen from inside the housing when a cover,which is an essential element of the electronic apparatus, is mounted.

As shown in the drawings, substantially square input device 11 isconstructed of component case 12 made of resin, first signal generators13 provided inside case 12, and operating member 11A, and is installedin housing 14 of the electronic apparatus.

Housing 14 is provided with locating opening 15 large enough to receivecase 12 of input device 11.

This opening 15 is a combination of circular opening 15A provided in atop side of housing 14 and having a larger diameter than component case12 in size, square opening 15B concentric with circular opening 15Apositioned above square opening 15B and matching up with case 12 inshape, and four retaining openings 15C each protruding outward from themiddle of each side of square opening 15B.

In regard to combination with cover 19 (described later), retainingopenings 15C are preferably formed so that a circular arc connectingrespective outer peripheries of four retaining openings 15C will besimilar in shape to circular opening 15A and will equal or will besmaller than opening 15A in size.

By having square opening 15B and retaining openings 15C, opening 15defines projections for housing 14. These projections referred to asstepped parts 15D are flat, have the same height and are positionedbelow the top side of housing 14.

Housing 14 accommodates internal members including wiring board 16.

Second signal generators 17 are arranged on wiring board 16. Each one ofthese generators 17 produces a specified output by functioning incombination with corresponding first signal generator 13 provided insideinput device 11.

Second signal generator 17 has terminal 18, which is soldered to wiringboard 16.

Cover 19 with which circular opening 15A is closed has a smallerdiameter than circular opening 15A and is constructed of ring-shapedflat plate 20 having through hole 20A in the middle thereof, and fourL-shaped poles 21-24 projecting downward from an outer border of abottom surface of flat plate 20. L-shaped poles 21-24 have respectivehorizontal parts 25-28 not connecting with flat plate 20, and thesehorizontal parts 25-28 have respective grooves 29-30 in their respectiveouter sides.

L-shaped poles 21-24 are provided at an equal angular pitch at a bottomside of cover 19, and horizontal parts 25-28 have respective leadingends oriented in the same direction.

Each one of horizontal parts 25-28 is shorter than each retainingopening 15C of opening 15.

After input device 11 is fit and positioned in square opening 15B ofopening 15 of housing 14, cover 19 is placed in such a manner thatL-shaped poles 21-24 are inserted into respective retaining openings15C. Cover 19 is thereafter turned clockwise with the bottom surface ofring-shaped flat plate 20 urged against stepped parts 15D, whereby eachone of horizontal parts 25-28 of poles 21-24 of cover 19 hitches on abottom surface of corresponding stepped part 15D. Cover 19 is thusmounted to housing 14, thereby fixing input device 11.

When cover 19 is turned clockwise, grooves 29-32 formed in therespective outer sides of L-shaped poles 21-24 of cover 19 engage withrespective projections 33-36 provided inside housing 14. This preventscover 19 from easily coming off when counterclockwise external forceacts on cover 19.

It is visually preferable that the thickness of flat plate 20 is equalto the depth of circular opening 15A so that a top surface of cover 19will be flush with the top side of housing 14 when cover 19 is securedby housing 14.

When cover 19 is secured by housing 14, input device 11 is fixed withoutfail because input device 11 is sandwiched vertically between wiringboard 16 and cover 19 with its component case 12 fitting in squareopening 15B.

According to the present embodiment described above, just installingcover 19 to housing 14 facilitates the installation of input device 11.

An operation of the electronic apparatus thus mounted with input device11 will be described hereinafter.

When operating member 11A of input device 11 is operated with a hand, afinger or the like, first signal generator 13 operates insynchronization with the movement of operating member 11A. Here, asignal is produced and transmitted to corresponding second signalgenerator 17 disposed on wiring board 16. This second signal generator17 then sends a specified output from its terminal 18 to an electronicdevice such as a microcomputer (not shown) via wiring board 16, andconsequently, the electronic apparatus starts a specific functioncorresponding to the signal.

When the operation of operating member 11A of input device 11 isstopped, first and second signal generators 13, 17 stop their respectiveoperations and return to a state in which no output signal is generated.

Input device 11 is replaced in the following manner. First, cover 19 isturned counterclockwise with force great enough to disengage grooves29-32 of L-shaped poles 21-24 from respective projections 33-36 untileach one of horizontal parts 25-28 of poles 21-24 that is hitched on thebottom surface of stepped part 15D of housing 14 returns tocorresponding retaining opening 15C. Cover 19 is then lifted off fromhousing 14.

Next, input device 11 positioned in square opening 15B of housing 14 isremoved, and new input device 11 is then placed in opening 15B.Thereafter, cover 19 is reinserted in opening 15 of housing 14 andturned clockwise to hitch each one of horizontal parts 25-28 of itspoles 21-24 on the bottom surface of each stepped part 15D and to engagegrooves 29-32 formed in the respective outer sides of horizontal parts25-28 with respective projections 33-36. Consequently, new input device11 is fixed by stepped parts 15D of housing 14, wiring board 16 andcover 19.

In a typical electronic apparatus, input device 11 having a mechanicallymovable part such as operating member 11A is well known for its highfrequency of failure. Input device 11 of the present invention issuperior in maintenance because as described above, device 11 can bereplaced with ease when failed.

In cases where input device 11 has failed, repair is simply a matter ofreplacing device 11 in the simple manner described above, so that thereis no need to troublesomely solder first signal generators 13 of inputdevice 11, second signal generators 17 and others to wiring board 16 andto detach them from board 16.

Cover 19 may be fixed to housing 14 by snap fitting or screwing insteadof turning the one having L-shaped poles 21-24 such as described above.

For relative ease of alignment between each first signal generator 13and each corresponding second signal generator 17, for example, inreplacement of input device 11, it is preferable that first signalgenerator 13 of input device 11 and second signal generator 17 disposedon wiring board 16 function in noncontact combination, using, forexample, magnetism or light.

For example, a magnet is used as first signal generator 13 of inputdevice 11, while a magnetic sensor such as a Hall device is used assecond signal generator 17 inside housing 14. In this case, first andsecond signal generators 13, 17 function in noncontact relation, and aspecified output is obtained from second signal generator 17.

In the above case, water-proof insulating sheet 37 can be disposedbetween first signal generators 13 of input device 11 and second signalgenerators 17 of housing 14 for protection from dust or water enteringfrom opening 15 in which input device 11 is placed, input device 11 perse or others. Consequently, the electronic apparatus can have adustproof and waterproof structure.

Instead of having insulating sheet 37, the electronic apparatus may havea wall, provided in the form of a box-shaped recessed part to cover theperiphery and bottom of opening 15 of housing 14, as a waterproofconstruction.

By using a light-emitting device such as a LED or an EL device, forexample, at wiring board 16 provided with second signal generators 17inside housing 14 and using light-transmitting material for cover 19 toallow cover 19 to guide light emitted by the light-emitting device tothe top side of housing 14, the periphery of input device 11 can beilluminated with this light. This improves visibility of the position ofinput device 11 and allows favorable operation, for example, even atnight.

Not only cover 19 but also component case 12 of input device 11 may bemade of light-transmitting material to guide the light emitted by thelight-emitting device.

As described above, the present embodiment facilitates the replacementof input device 11 which can be removed by just detaching cover 19 fromhousing 14 without removing housing 14 from the electronic apparatus.

The present invention is applicable to cases where a stick, a pad, arolling member or the like is mounted as operating member 11A of inputdevice 11, and each first signal generator 13 operates in accordancewith the operation of such operating member 11A.

Exemplary Embodiment 2

The second exemplary embodiment of the present invention will bedescribed hereinafter.

In the present embodiment, a trackball device capable of detectingoperation and a signal through use of magnetism is mounted in anelectronic apparatus in place of input device 11 such as described inthe first exemplary embodiment. Elements similar to those in the firstembodiment have the same reference marks and will not described indetail.

FIGS. 3 and 4 are an exploded perspective view and a sectional view,respectively, of the electronic apparatus in accordance with the secondembodiment of the present invention. FIG. 5 is a top plan view of thesame electronic apparatus from which a housing, and a case of thetrackball device are omitted, and FIG. 6 is a sectional view taken alongline A-A of FIG. 5. FIG. 7 is a top plan view of the same electronicapparatus from which the housing, the case of the trackball device, aball, rollers and others are omitted.

As shown in these drawings, the electronic apparatus of the presentembodiment has trackball device 40 placed in opening 15 of housing 14 asinput device 11. Cover 19 is mounted and fixed to housing 14 from theupper side, so that trackball device 40 is positioned.

First, a description will be provided of this trackball device 40.

As shown in FIGS. 4 and 5, XI roller 42 and XII roller 43 are disposedin opposed relation, and YI roller 44 and YII roller 45 are disposed inopposed relation. These rollers 42-45 each have the shape of a roundshaft and are arranged in a square configuration in the vicinity ofrespective sides of a top surface of square base 41 molded out of resin,so that one pair of rollers is orthogonal to the other pair of rollers.Supports 46-49 formed integrally with base 41 rotatably support rollers42-45, respectively.

Contact parts 42A, 43A, 44A, 45A provided at respective middle parts ofXI roller 42, XII roller 43, YI roller 44 and YII roller 45 are inrespective positions slightly lower than a center of ball (operatingmember) 50 of trackball device 40 and are positioned around ball 50 toeach face ball 50 across an established clearance.

Respective contact parts 42A-45A of XI roller 42 to YII roller 45 arecircular in section and have specific recessed and projected parts inrespective equally divided positions in circumference.

As shown in FIGS. 5 and 6, rollers 42-45 have, at their respective ends,magnets (first signal generators) 51-54 each magnetized with north andsouth poles alternating every 90°. These magnets 51-54 rotate insynchronization with respective rotating rollers 42-45.

As shown in FIGS. 3 and 4, case 55 of trackball device 40 is fixed onbase 41 to form a component case in cooperation with base 41. This case55 is made of resin and has circular hole 55A in the center of its topsurface and peripheral wall 55B extending downward from an outer edge ofits top surface. Circular hole 55A has a smaller diameter than ball 50to allow an upper portion of ball 50 stored in case 55 to project, and alower edge of peripheral wall 55B is fixed to base 41. Thus, trackballdevice 40 does not let go of ball 50 under normal conditions.

As shown in FIG. 4, ball 50 is pushed from beneath by one end ofresilient cantilever plate spring 56, the other end of which is fixedinto base 41 by insert molding or the like. When ball 50 is in such anormal condition as not to be operated, circular hole 55A in the centerof the top surface of case 55 is closed by the upper end portion of ball50.

Ball 50 is vertically movable in a space defined by case 55 and base 41since a lower end portion of ball 50 pushes plate spring 56 down whendownward pressing force is applied to ball 50.

After trackball device 40 thus configured is placed in opening 15 ofhousing 14 as described earlier, cover 19 is mounted. Consequently, thecomponent case (a combination of base 41 and case 55) is restrictedsideways by a sidewall of each stepped part 15D of housing 14 andsandwiched vertically between wiring board 57 disposed inside housing 14and cover 19, thereby being fixedly installed in the electronicapparatus.

As shown in FIG. 6, magnetic sensors 58-61 are disposed on wiring board57 inside housing 14 with their respective terminals 58A-61A soldered towiring board 57. These magnetic sensors 58-61 are second signalgenerators functioning in combination with respective magnets (firstsignal generators) 51-54 of trackball device 40 to output specifiedsignals.

Magnetic sensors 58-61 are provided in respective positionscorresponding to respective magnets 51-54 attached to respective rollers42-45 of trackball device 40.

These sensors 58-61 and a top side of wiring board 57 are collectivelycovered with flexible insulating sheet 62.

A central part of a configuration of magnetic sensors 58-61 arranged onwiring board 57 corresponds to the position of the lower end portion ofball 50 of trackball device 40. Wiring board 57 is formed with, at thiscentral part, self-restoring push switch 63.

This self-restoring push switch 63 includes outer fixed contact 64formed of metallic foil or the like on wiring board 57, domelike movablecontact 65 formed of a convex, resilient metal sheet, and central fixedcontact 66 provided on wiring board 57 below a central portion ofmovable contact 65. Movable contact 65 and central fixed contact 66 faceeach other across an established space, and a top surface of movablecontact 65 is covered with flexible insulating film 67 having anadhesive layer on its bottom surface.

Push switch 63 having the above-described structure is low-profile andcan be constructed at low cost. This push switch 63 also has highperformance because switch 63 restores itself and has a click feel inoperation.

Domelike movable contact 65 has resilient restitutive force set equal toor greater than specified resilient restitutive force so as not to beturned inside out by being pressed by ball 50 when ball 50 is in normalcondition or in rolling operation.

It is not necessary for wiring board 57 to be formed with self-restoringpush switch 63. Switch 63 may be mounted to wiring board 57 as acompleted low-profile single push switch.

Referring to FIGS. 8 and 9, a description will be provided next of anoperation of the electronic apparatus in accordance with the presentembodiment.

FIG. 8 is a sectional view taken along line X-X of FIG. 5, illustratingball 50 of the trackball device in rolling operation, and FIG. 9 is asectional view illustrating ball 50 in pressing operation.

First, a description will be provided of a leftward rolling operation ofball 50 that follows the normal condition illustrated by FIGS. 4 and 6in which trackball device (input device) 40 of the electronic apparatusof this embodiment is not in operation. The leftward rolling operationis rolling of ball 50 leftward, that is, in a direction indicated by anarrow of each one of FIGS. 6 and 8 with a hand or a finger touching theupper portion of ball (operating member) 50 projecting upward throughcircular hole 55A of case 55 of trackball device 40.

When rolled leftward, ball 50 contacts only contact part 42A of XIroller 42 positioned in the direction of the operation, or ball 50contacts contact part 42A of XI roller 42 and either contact part 44A ofYI roller 44 or contact part 45A of YII roller 45 at the same time.

Here, ball 50 rotates while contacting the recessed and projected partsprovided at contact part 42A of XI roller 42, which is positioned in thedirection of the operation, at right angles, thereby generatingfrictional force great enough to rotate XI roller 42, and consequently,XI roller rotates.

Even when ball 50 comes into contact with either contact part 44A of YIroller 44 or contact part 45A of YII roller 45 that is disposed along adirection orthogonal to the direction of the operation, ball 50 contactsthe recessed and projected parts of contact part 44A or 45A in asubstantially horizontal direction, so that any one of YI roller 44 andYII roller 45 is not provided with enough frictional force for rotation.Consequently, ball 50 runs idle, and YI roller 44 and YII roller 45 donot rotate.

As XI roller 42 rotates, magnet (first signal generator) 51 provided atthe end of roller 42 rotates accordingly, and the north and south polesof magnet 51 alternately and repeatedly approach corresponding magneticsensor (second signal generator) 58 disposed below magnet 51 on wiringboard 57.

As the north pole of magnet 51 approaches magnetic sensor 58, magnetismof the north pole that acts on magnetic sensor 58 increases accordingly,and sensor 58 produces a larger positive output voltage accordingly.

As the south pole approaches sensor 58, magnetism of the south pole thatacts on sensor 58 increases accordingly, and sensor 58 produces a largernegative output voltage accordingly.

In other words, when the output voltage from terminal 58A of magneticsensor 58 exceeds a specified value, an ON state is established, and anOFF state is established when the output voltage is at or below thespecified value. A corresponding signal is processed by a microcomputer(not shown) or the like for generation of a digital signal.

This allows determination of the number of revolutions of XI roller 42,and based on the number of revolutions, the amount of movement of acursor or the like, which is displayed on a display screen of theelectronic apparatus, in a positive or negative direction on the x-axisis determined.

When ball 50 is rolled rightward, XI roller 42 does not rotate, but XIIroller 43 rotates, and the amount of movement of the cursor, displayedon the screen, in a direction opposite to the above-mentioned leftwardrolling operation on the x-axis is determined. When ball 50 is rolledforward or backward in the drawing, XI roller 42 and XII roller 43 donot rotate, but opposed YI roller 44 and YII roller 45 rotate, and theamount of movement in a positive or negative direction on the y-axis isdetermined.

When ball 50 is rolled diagonally in the drawing, one of XI roller 42and XII roller 43 and one of YI roller 44 and YII roller 45 rotate, andthe amount of movement of the cursor in the specified direction definedby the x- and y-axes is determined based on the rolling direction andcomponents of ball 50.

In the above description, magnets 51-54 of XI roller 42 to YII roller 45of trackball device 40 are each magnetized with the north and southpoles alternating every 90°. This means that the signal is producedtwice during one rotation of each one of rollers 42-45. However, thenumber of times the signal is produced may be increased or decreased onas a needed basis.

When the upper portion of ball 50 is pressed with the finger or the likein the normal condition (illustrated by FIG. 4) after the arrival of thecursor in a desired position on the display screen through the rollingoperation of ball 50, ball 50 pushes down plate spring 56, disposedbelow ball 50, as shown in FIG. 9. Consequently, projection 56A of platespring 56 presses, at its bottom surface, a central portion of the toppart of push switch 63, that is, the central portion of domelike movablecontact 65 downward via insulating sheet 62.

When this downward pressing force exceeds a specified value, domelikemovable contact 65 is resiliently turned inside out with the click feel.Here, a bottom surface of the central portion of movable contact 65contacts central fixed contact 66 as shown in FIG. 9, whereby conductionis established between outer and central fixed contacts 64, 66 throughmovable contact 65.

Here, a signal is transmitted as a signal identifying the position ofthe cursor on the display screen to a circuit of the electronicapparatus mounted with trackball device 40 through a circuit (not shown)on wiring board 57.

When the downward pressing force applied to ball 50 is released,domelike movable contact 65 restores its original domelike shape by itsown resilient restoring force and pushes ball 50 back from beneathinsulating sheet 62 and projection 56A of plate spring 56. Consequently,outer and central fixed contacts 64, 66 of push switch 63 areelectrically disconnected from each other.

In addition, ball 50 is pushed up until it is urged against circularhole 55A of case 55 by the restoring force of cantilever plate spring56, thus returning to the normal condition illustrated by FIG. 4.

Insulating sheet 62 may have a domelike portion corresponding to pushswitch 63 to function in place of plate spring 56. In this case, thedomelike portion urges ball 50 upward by contacting the lower endportion of ball 50, thereby closing circular hole 55A of case 55.

According to the present embodiment described above, the cursordisplayed on the screen can be moved easily with high definition throughthe rolling operation of ball 50, and the signal identifying theposition of the cursor can be produced by operating push switch 63,positioned below ball 50, through the pressing operation of ball 50. Theobtained electronic apparatus equipped with the push switch and thetrackball device thus operates stably and allows a small projected area.

Even this embodiment eliminates the need to open housing 14 for removalof wiring board 57, thereby facilitating the replacement of trackballdevice 40 when, for example, a structurally operating part of trackballdevice 40 has failed. The present embodiment is also similar to thefirst embodiment in that the electronic apparatus has a dustproof andwaterproof structure since magnetic sensors 58-61 and the top side ofwiring board 57 are collectively covered with waterproof insulatingsheet 62.

Exemplary Embodiment 3

The third exemplary embodiment of the present invention will bedescribed hereinafter.

As in the case with the electronic apparatus of the second exemplaryembodiment, an electronic apparatus of the present embodiment isequipped with magnetic trackball device 40 as an input device. In thisembodiment, second signal generators differ from those of the secondembodiment, and the description deals mainly with these second signalgenerators.

Elements (e.g., elements of trackball device 40) similar to those in thefirst and second embodiments have the same reference marks and will notbe described in detail.

FIG. 10 is a top plan view of the electronic apparatus, from which ahousing, a case of the trackball device, a ball and rollers are omitted,in accordance with the third embodiment of the present invention.

As shown in this drawing, the present embodiment differs structurallyfrom the second embodiment illustrated by FIG. 7 in that the secondsignal generators mounted on wiring board 57 are four reed switches71-74.

These four reed switches 71-74 are disposed on wiring board 57 of theelectronic apparatus with their respective terminals 71A-74A soldered toboard 57. As in the case of the second embodiment, these second signalgenerators are provided in respective positions corresponding torespective magnets (first signal generators) 51-54 (not shown in FIG.10) attached to respective XI roller 42 to YII roller 45 (not shown inFIG. 10) rotatably supported by base 41.

As north and south poles of magnets 51-54 mounted to respective rollers42-45 change their positions relative to each other through rotations ofrollers 42-45, reed switches 71-74 repeatedly switch back and forthbetween ON and OFF accordingly. In this way, reed switches 71-74 outputdigital signals.

Except for the reed switches, the structure of the present embodiment issimilar to that of the second embodiment and will not be described.

Next, a description will be provided of an operation of thethus-configured electronic apparatus in accordance with the presentembodiment.

When ball 50 of trackball device 40 is rolled leftward, XI roller 42positioned in the rolling direction of ball 50 rotates as in the case ofthe second embodiment. Accordingly, magnet (first signal generator) 51rotates, and its north and south poles alternately and repeatedlyapproach corresponding reed switch (second signal generator) 71 as inthe case of the second embodiment.

When the north pole or the south pole of magnet 51 are in a specifiedregion with respect to reed switch 71, reed switch 71 is in the ONstate, and switch 71 changes to the OFF state when the north and southpoles deviate from the specified region. Reed switch 71 thus producesthe digital signal corresponding to the rotation of magnet 51.

In this way, the number of revolutions of roller 42, that is, the amountof movement of a cursor, displayed on a display screen of the electronicapparatus including trackball device 40, in the specified direction isdetermined. This is similar to the case of the second embodiment.

Even in cases where ball 50 is rolled in a different direction, asimilar operation takes place, and the reed switch corresponding to thedirection of the operation produces the digital signal.

In the present embodiment, the electronic apparatus operates similarlyto that of the second embodiment when ball 50 of trackball device 50 ispressed, and trackball device 40 is mounted in a manner similar to thatof the second embodiment, so that their descriptions are omitted.

According to the present embodiment described above, reed switches 7174are disposed as the second signal generators, so that each of theiroutputs can be obtained in the form of the digital signal. Thus, theelectronic apparatus does not require an A/D conversion circuit forprocessing a signal and has simplified circuitry.

Exemplary Embodiment 4

The fourth exemplary embodiment of the present invention will bedescribed hereinafter.

In an electronic apparatus of the present embodiment, a part where inputdevice 11 is mounted differs in structure from that of the firstembodiment, and the description deals mainly with this part, referringto the accompanying drawings.

FIG. 11 is a perspective view of an essential part of the electronicapparatus in accordance with the fourth embodiment of the presentinvention, and FIG. 12 is an exploded perspective view of the sameelectronic apparatus. FIG. 13 is a sectional view taken along line B-Bof FIG. 12, illustrating the electronic apparatus in complete condition.

As shown in these drawings, the electronic apparatus of the presentembodiment utilizes housing 81 per se for positioning and mounting inputdevice 11.

In other words, the structure of the present embodiment does not includecover 19 (see FIG. 1) such as described in the first embodiment. Thisallows the reduced number of parts.

As shown in FIGS. 11 and 12, housing 81 has opening 81A which isprovided in place to correspond to operating member 11A of input device11, and in the vicinity of opening 81A, locating recess 81Bcorresponding to the shape of an upper part of component case 12 ofinput device 11 is provided in a reverse side of housing 81.

Although elements such as other operating members are not shown in thedrawings, housing 81 is provided with those elements on its side havingopening 81A. In other words, the side of housing 81 that faces operatingmember 11A of input device 11 defines a main operating surface of theelectronic apparatus.

On wiring board 16 disposed inside housing 81, second signal generators17 are disposed in respective positions corresponding to opening 81A andrecess 81B by soldering or the like.

Each one of second signal generators 17 produces a specified outputsignal by functioning in noncontact combination with each correspondingfirst signal generator (not shown) provided inside input device 11.

Although elements such as other electronic parts are not shown in thedrawings, those elements are mounted on wiring board 16 with secondsignal generators 17, and those elements, second signal generators 17and a top side of board 16 are collectively covered with insulatingsheet 37.

Thus, wiring board 16 and those elements, such as second signalgenerators 17 and other electronic devices, which are mounted on board16, can be protected without fail from dust or water entering fromopening 81A of housing 81 or holes or slits, formed for other operatingmembers in the side having opening 81A.

Input device 11 is positioned and mounted by being sandwiched betweenrecess 81B of housing 81 and insulating sheet 37 covering wiring board16 after its operating member 1A is inserted through opening 81A ofhousing 81. Since the upper part of component case 12 of input device 11is inserted in recess 81B, case 12 and recess 81B engage sideways witheach other, whereby input device 11 is positioned in a directionparallel to wiring board 16. Moreover, input device 11 is positionedvertically because a top surface of case 12 is pressed down by thereverse side of housing 81 at recess 81B, while a bottom surface of case12 is supported by insulating sheet 37 over wiring board 16.

Rattle or the like produced by input device 11 can be reduced if softinsulting sheet 37 is used and pressed slightly along its thickness bythe bottom surface of case 12 in installation. Input device 11 thusobtained is of high quality.

As mentioned above, the electronic apparatus of the present embodimenthas the reduced number of elements, and the part of input device 11 thatincludes operating member 11A can be removed for replacement by justopening housing 81.

In the present embodiment, an operation and others of input device 11are similar to those described in the first embodiment and will not bedescribed.

In this embodiment, housing 81 has been utilized to hold input device 11down. However, input device 11 may be positioned and mounted by use ofanother member.

Input device 11 using the first signal generators in noncontactcondition for operation is not limited to a stick type input device suchas described above. For example, the input device may be trackballdevice 40 such as described in the second embodiment, or may use arolling member such as a ball or a roller as the operating member or apad for specified input operation.

The present invention's structure for mounting the input device is alsoapplicable to elements other than input device 11.

INDUSTRIAL APPLICABILITY

An electronic apparatus of the present invention that includes an inputdevice has first signal generators disposed inside the input device, andsecond signal generators disposed in a housing, and these second signalgenerators function in combination with the first signal generators,respectively. The replacement of the input device is easy because itdoes not require removal of a wiring board disposed inside the housing,and the electronic apparatus is excellently maintainable and hasexcellent reliability.

The first and second signal generators operate in noncontact relation.This facilitates improvement of the apparatus's resistance to dust andwater.

The use of a trackball device as the input device allows fine inputoperation such as selecting, deciding on or confirming a requiredoperation. Since an output from each one of the second signal generatorscan be obtained in the form of a digital signal, the electronicapparatus can have simplified circuitry and is inexpensive and easy touse.

List of Reference Marks 11 input device 11A operating member 12component case 13 first signal generator 14, 81 housings 15, 81Aopenings 15A circular opening 15B square opening 15C retaining opening15D stepped part 16, 57 wiring boards 17 second signal generator 18,58A-61A, terminals 71A-74A 19 cover 20 flat plate 20A through hole 21-24L-shaped poles 25-28 horizontal parts 29-32 grooves 33-36 projections37, 62 insulating sheets 40 trackball device 41 base 42 XI roller42A-45A contact parts 43 XII roller 44 YI roller 45 YII roller 46-49supports 50 ball 51-54 magnets 55 case 55A circular hole 55B peripheralwall 56 plate spring 56A projection 58-61 magnetic sensors 63 pushswitch 64 outer fixed contact 65 domelike movable contact 66 centralfixed contact 67 insulating films 71-74 reed switches 81B recess

1. An electronic apparatus comprising: an input device including firstsignal-generating-means; a housing having an opening for mounting saidinput device; a cover, detachable from said housing, for fixing saidinput device when installed in said opening of said housing; and secondsignal-generating-means provided inside said housing, said secondsignal-generating-means functioning in combination with said firstsignal-generating-means, wherein a plurality of projections are providedinside said housing, said cover includes a ring-shaped flat plate and aplurality of L-shaped poles projecting downward from an outer border ofthe bottom surface of said flat plate, and a groove is provided in anouter side of respective one of said plurality of L-shaped poles toengage with respective one of said plurality of projections, whereinsaid first signal-generating-means and said secondsignal-generating-means form a trackball device, wherein said trackballdevice includes a ball, a base, two X rollers and two Y rollers providedinside said base, and rotation of said ball makes said X rollers and Yrollers rotate, and if said ball is pushed down, said ball pushes a pushswitch provided on a wiring board disposed in a lower portion of saidbase, wherein said first signal-generating-means of said trackballdevice includes a magnet, and said second signal-generating-means ofsaid trackball device includes a magnetic sensor, wherein said trackballdevice comprises: the ball; four round rollers each disposed orthogonalto said ball, each of said rollers facing said ball across a clearanceand having a recessed and projected part at a part thereof whichcontacts said ball, the four round rollers constitute said X rollers andY rollers; and said magnet rotatably fixed to one end of each of saidrollers to serve as said first signal-generating-means, wherein saidmagnet rotates in accordance with rotation of one of said four rollersthat contacts said ball, thereby changing magnetism when said ball isrolled.
 2. The electronic apparatus of claim 1, wherein said cover ismade of light-transmitting material.
 3. The electronic apparatus ofclaim 1, wherein said first signal-generating-means and said secondsignal-generating-means are out of contact with each other.
 4. Theelectronic apparatus of claim 3, wherein said secondsignal-generating-means is mounted to a wiring board disposed insidesaid housing, and said second signal-generating-means and said wiringboard are covered with an insulating sheet.
 5. The electronic apparatusof claim 1, wherein said trackball device includes a vertically movableball, and a switch which operates in relation to vertical movement ofsaid ball is provided on a wiring board on which said secondsignal-generating-means is disposed.
 6. The electronic apparatus ofclaim 1, wherein said trackball device includes a ball, and said ball ispressed against a circular hole of a component case from inside saidcomponent case by a resilient member disposed below said ball.
 7. Theelectronic apparatus of claim 1, wherein said opening of said housingincludes a circular opening which is closed by said cover, a squareopening and a plurality of retaining openings which retain said inputdevice, and a plurality of stepped parts which form said square openingand said plurality of retaining openings, each having a plane portionbeing lower than a top surface of said housing, and when said coverengages with said opening, a top surface of said cover is substantiallyflush with said top surface of said housing.